Combining Meyer–Schuster Rearrangement with Aldol and Mannich Reactions: Theoretical Study of the Intermediate Interception Strategy.
Interception of the transient allenyl enolate intermediate of the vanadium-catalyzed Meyer–Schuster rearrangement with aldehydes and imines has been studied computationally using density functional theory. Mechanistic details of the catalytic cycles for each of the reaction variants are established....
| Publicado en: | Journal of the American Chemical Society Vol. 134; no. 46; pp. 19159 - 19170 |
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| Autores principales: | , |
| Formato: | Artículo |
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American Chemical Society
11/21/2012
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| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=hlh&AN=83882327&site=ehost-live header: @attributes: shortDbName: hlh uiTerm: 83882327 longDbName: Humanities International Complete uiTag: AN controlInfo: bkinfo: jinfo: jid: 00027863 ACS jtl: Journal of the American Chemical Society issn: 00027863 maglogo: N pubinfo: dt: 11/21/2012 vid: 134 iid: 46 pid: 997 pub: American Chemical Society artinfo: ui: 83882327 10.1021/ja307892c ppf: 19159 ppct: 11 formats: tig: atl: Combining Meyer–Schuster Rearrangement with Aldol and Mannich Reactions: Theoretical Study of the Intermediate Interception Strategy. aug: au: Kalek, Marcin Himo, Fahmi affil: Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, S-106 91 Stockholm, Sweden su: Rearrangements (Chemistry) Computational chemistry Density functionals Mannich reaction Catalytic isomerization Intermediates (Chemistry) Carbon-carbon bonds synthesis Aldols sug: subj: Rearrangements (Chemistry) Computational chemistry Density functionals Mannich reaction Catalytic isomerization Intermediates (Chemistry) Carbon-carbon bonds synthesis Aldols ab: Interception of the transient allenyl enolate intermediate of the vanadium-catalyzed Meyer–Schuster rearrangement with aldehydes and imines has been studied computationally using density functional theory. Mechanistic details of the catalytic cycles for each of the reaction variants are established. In particular, it is shown that the active form of the catalyst contains two triphenylsiloxy ligands, the transesterification of vanadate occurs via σ-bond metathesis, and vanadium enolate is directly involved in the key C–C bond formation. The calculations also provide support for the dissociative course of the key 1,3-shift step. The stereochemistry of the reaction is thoroughly investigated, and the obtained energy barriers reproduce and rationalize the experimentally observed (Z)-, (E)-selectivity. The calculated free energy profiles are analyzed in terms of efficiency of the intermediate enolate interception. It is shown that the investigated reactions represent borderline cases, in which the intermediate trapping is only slightly favored over the undesired isomerization pathway. pubtype: Academic Journal doctype: Article src: R language: English refInfo: copyright: @attributes: flag: Y dt: @attributes: year: 2012 holdings: @attributes: islocal: N |
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